The American Institute for Cancer Research recommends diets high in fruits and vegetables to reduce cancer risk.

They and other health authorities persistently urge people to eat more produce because population studies link diets rich in whole plant foods — fruits, vegetables, whole grains, beans, nuts, and seeds — to lower risks for common cancers.

While the vitamins and minerals in plant foods are essential to life and basic health, their antioxidants (and fibers) bring unique and powerful preventive-health benefits.

You’ll find dozens of reports on relevant scientific research in the “Antioxidants” section of our news archive, many of which concern links between dietary antioxidants and specific health conditions or broader anti-aging affects.

And the encouraging results of new Spanish research link a common category of antioxidants to reduced risks for breast cancer.

Spanish study links polyphenols to reduced breast riskThe new findings were presented at the European Congress on Obesity (ECO) in Glasgow, Scotland.

Spanish researchers, led by Andrea Romanos Nanclares, MSc, knew that common foodborne antioxidants called polyphenols are strongly linked to reduced risks for major chronic diseases.

As obesity-focused researchers, the Spanish team knew that postmenopausal breast cancer is one of the most common and dangerous cancers afflicting overweight women.

No previous studies had looked for links between polyphenol intakes and the risk that a postmenopausal woman will develop breast cancer, so their study was designed to look for any such links.

The Spanish team recruited 11,028 female graduates of Seguimiento Universidad de Navarra (SUN), who completed a diet questionnaire so that the researchers could estimate each woman’s average polyphenol intake.

The women were followed for an average 11.8 years, and the researchers calculated a strong link between higher intakes of certain polyphenols and a substantially reduced risk for breast cancer.

Protective polyphenol-type antioxidants — called hydroxycinnamic acids — abound in many fruits and vegetables, and especially in coffee.

Additionally, the 11,028 participating women were categorized into one of three groups (tertiles), based on their intake of hydroxycinnamic acids.

This grouping revealed that the women who consumed the most hydroxycinnamic acids were 62% less likely to develop breast cancer, compared to the women with the lowest intakes.

When the team dug deeper, they found the lowest breast-cancer risk among the women with the highest intakes of a subgroup of hydroxycinnamic acids called chlorogenic acids, which are found in many fruits and vegetables, but at especially high levels in coffee.

Specifically, the women who consumed the most chlorogenic acids were 65% less likely to develop postmenopausal breast cancer, compared to those who consumed the smallest amounts.

Key facts about the “antioxidants” in plant foodsThe polyphenol and carotenoid compounds found in whole plant foods are commonly called “antioxidants” because they generally behave that way in test tube experiments.

This explains the cartoonish ads for POM Wonderful brand pomegranate juice, which portray its polyphenols and other flavonoids as antioxidant superheroes that slay cell-damaging free-radical dragons.

While it’s true that the antioxidants in plant foods are potent health protectors, they don’t exert direct antioxidant effects in the body … at least not to a very significant extent.

Instead, they exert most of their beneficial effects on oxidation and inflammation indirectly, via so-called “nutrigenomic” influences on genetic “switches” in our cells. For more on this, see Food-Borne Antioxidants Mostly Act Indirectly.

Because different antioxidants bring different benefits, it's wise to consume a broad range of plant foods, including fruits, vegetables, nuts, beans, mushrooms, and whole grains.

European Association for the Study of Obesity (EASO). Study shows high phenolic acid intake -associated with a healthy diet -- is associated with reduced breast cancer risk. April 30, 2019. Accessed at https://www.eurekalert.org/pub_releases/2019-04/eaft-ssh043019.php